Renal Masses

Abstract

The widespread use of diagnostic ultrasound and MDCT for a variety of clinical entities has led to an increase in the detection of renal masses (Smith et al. in Radiology 170(3 Pt 1):699–703,1989). The earlier a mass is detected on imaging, the higher the likelihood of it being early stage and low grade (Tsui et al. in J Urol 163(4):1090–1095, 2000), and therefore amenable to nephron-sparing surgery as opposed to total nephrectomy. Various therapeutic options exist for treatment of localized renal cell carcinoma: Open or laparoscopic total or partial nephrectomy, laparoscopic and percutaneous ablational therapies such as radiofrequency ablation (RFA) and cryotherapy, or minimally invasive catheter techniques like super selective chemoembolization. Against this background, the imaging-based selection of the right therapeutic strategy for each individual patient becomes more and more important. Furthermore, prognosis and outcome are influenced by tumor stage and grade at the time of diagnosis. Because of its high diagnostic power, MDCT can be applied as the primary and definitive diagnostic imaging method in differentiation of renal masses that are indeterminate or suspicious at IVU or ultrasound, e.g., cystic lesions, tumors, pseudotumors, calcifications, or arteriovenous malformations. Recent advances in MDCT technology, namely the introduction of dual energy CT (DECT), iterative reconstruction of image data, and associated advanced dose reduction strategies have a great impact on the routine use of MDCT for the workup of patients with renal masses. This chapter will focus on both state-of-the-art MDCT applications and recent developments in patients with renal tumors. Furthermore, the TNM staging system will be reviewed.